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Biomedical subjects

S Takamoto

Publications and source records attributed to S Takamoto.

At least 271 records · Page 15Linked to original sources
PubMed1985

Intraoperative color flow mapping by real-time two-dimensional Doppler echocardiography for evaluation of valvular and congenital heart disease and vascular disease.

We have developed real-time two-dimensional Doppler echocardiography, which can display color flow mapping on a two-dimensional echocardiogram. Intraoperative two-dimensional Doppler echocardiography was performed during cardiovascular operations before and after the definitive procedure in 33 patients, 14 with valvular disease, eight with congenital heart disease, and 11 with vascular disease. Its clinical usefulness was evaluated. In patients with valvular heart disease, 13 valve replacements, 10 valvuloplasties, and four untouched lesions were assessed. No paravalvular leakage and three instances of minimal physiological transvalvular leakage from St. Jude Medical valves in the mitral position were noticed. Regurgitation after valvuloplasty was graded by extent of the regurgitant flow. This grading, comparable to postoperative grading, indicated no need for an additional procedure. In congenital heart disease, preoperative diagnoses were confirmed. The effect of the corrective operation was evaluated and no significant leakage or stenosis was found. Interatrial shunt flow was shown to increase after operative balloon atrial septostomy in a patient with dextro-transposition of the great arteries. In 11 patients with dissecting aortic aneurysm, the aneurysm was totally visualized in the operative field, including the structure and flow dynamics. In two patients, the preoperative cineangiographic diagnosis regarding involvement of dissection was corrected. After the vascular procedure, sufficient flow in the major aortic branches was confirmed in all patients and minimal leakage at the suture line was noticed in four patients. In conclusion, intraoperative color flow mapping by two-dimensional Doppler echocardiography has enabled the precise diagnosis and the necessary operation to be determined before cardiopulmonary bypass. It has also allowed the effects of the operation to be assessed before chest closure.

Adult↗
PubMed1984

Dynamic patch artificial myocardium; effects on the residual myocardial function.

Dynamic patch artificial myocardium (D-PATCH) has been developed to replace the damaged left ventricular (LV) wall in severe cardiogenic shock patients with a massive myocardial infarction. This study was undertaken to demonstrate the effects of (1) single D-PATCH support on the global cardiac function (group 1, 12 dogs, whole heart model), (2) single D-PATCH support on the LV function and myocardial metabolism (group 2, 6 dogs, right heart bypass model), and (3) the concomitant support of D-PATCH and aortic counterpulsation (CP) on the regional myocardial function of the residual LV wall (group 3, 6 dogs, right heart bypass model with ultrasonic piezoelectric crystals). In group 1, mean aortic pressure and cardiac output were increased 20-36% (p less than 0.01) and 17-50% (p less than 0.01) respectively, and mean left atrial pressure was decreased 16% (p less than 0.01) by D-PATCH assist. In group 2, under constant preload volume, afterload pressure and heart rate, tension time index (TTI) was decreased 21-26% (p less than 0.01) and myocardial oxygen consumption was also decreased 24-29% (p less than 0.001) by D-PATCH assist. In group 3, although peak LVP was increased by single D-PATCH assist, when heart was assisted concomitantly by D-PATCH and CP peak LVP was significantly decreased (18%, p less than 0.01). Percent LV segmental shortening was not increased by CP assist, but increased 143% (p less than 0.02) by D-PATCH assist. In conclusion, D-PATCH can improve the global LV function and myocardial metabolism of the ischemic failing heart, also improve the regional myocardial function of the residual LV wall. Thus, D-PATCH is effective for the salvage of ischemic myocardium while maintaining the global cardiac function.

Animals↗
PubMed1984

The development of real-time two-dimensional Doppler echocardiography and its clinical significance in acquired valvular diseases. With special reference to the evaluation of valvular regurgitation.

A noninvasive method for real time blood-flow imaging using ultrasound has long been required in the fields of cardiology and cardiovascular surgery. Recently, we developed a method of two-dimensional Doppler echocardiography (hereafter abbreviated as "2-D Doppler") for clinical use which allows us to obtain noninvasively, intracardiac blood-flow images in real time. The main purpose of this paper is to describe the newly developed blood-flow imaging system "2-D Doppler" and to demonstrate its clinical usefulness in acquired valvular diseases, particularly in the evaluation of valvular regurgitation. The device, in principle, combines a conventional pulsed-Doppler system and a newly developed auto-correlator, in which blood-flow images within a given cross section of a beating heart are noninvasively displayed in real time, simultaneously with conventional two-dimensional echocardiograms. The system can provide three kinds of information, direction, velocity and turbulence of blood flow. The 2-D Doppler examinations were carried out on 72 patients with acquired valvular diseases whose diagnoses were confirmed by angiography and/or surgery. Studies were performed comparing the findings of the 2-D Doppler and those of angiography (for aortic and mitral lesions) or with operative findings (for tricuspid lesions) in the quantitative evaluation of valvular regurgitation. Aortic, mitral and tricuspid valvular regurgitation have been quantitatively demonstrated with 2-D Doppler, and, for each value, the severity of the regurgitation showed a high correlation between the findings of 2-D Doppler and of angiography or surgery. In conclusion, we have found that (1) 2-D Doppler is very useful in detecting and estimating the severity of valvular regurgitation, and that (2) 2-D Doppler may replace conventional angiography in some situations.

Aortic Valve Insufficiency↗
PubMed1984

Five antigens on human T cells detected by mouse monoclonal antibodies.

Five antigen systems were defined by the monoclonal antibodies (MoAb) produced against mature T cells. The antigens recognized were grouped into two categories based on the antigen distribution on T cells. (a) Tp 120 [mol. wt 120 kilodaltons (120kD)] and Tp40 (40kD), these are on most peripheral T cells, but not on any other cell lineages, i.e. pan-T antigen. (b) Ts32 (32kD), Ts145 (145kD) and TsA (not determined), these antigens are present only on certain populations of peripheral T cells, i.e., T subset antigen. Among these five, Ts145 and TsA are probably novel T cell antigens. Cell surface phenotypes of leukaemias and lymphomas were typed with these MoAb. Ia like antigen negative, null cell type acute lymphocytic leukaemia (Ia- null ALL) are Tp40+, suggesting that this type of ALL belongs to a T cell lineage. T cell ALL (T-ALL) and lymphoblastic lymphoma (LL) were both Tp40+, Ts32+, TsA+ and a half of the cases were Tp120+, but the expression of Tp40 was stronger on LL cells. Mature T cell (T2) lymphoma and adult T cell leukaemia (ATL) were Tp120+, TsA+, while Tp40 was weakly expressed on only one third of the cases. These MoAb were found to be useful to estimate the origin of various T cell malignancies.

Animals↗
PubMed1984

[Antitumor activities and mechanisms of action of harringtonine and homoharringtonine].

The antitumor activities and the mechanisms of action of harringtonine and homoharringtonine, alkaloids isolated from cephalotaxus hainanensis Li, were compared to those of vincristine. The results obtained were as follows: Harringtonine and homoharringtonine Significantly inhibited the growth of L1210 cells in culture. The IC50 values were similar to that of vincristine. Harringtonine and homoharringtonine had little effects on changes in the DNA histograms of FL cells at any concentrations, which suggesting that these drugs prolong the duration of each phase of the cell cycle evenly. Harringtonine and homoharringtonine had only a minor effect in arresting P388 cells in mitosis. Harringtonine significantly inhibited the DNA synthesis of P388 leukemia cells in culture, while vincristine weakly inhibited RNA and DNA synthesis. The successive treatment with harringtonine and homoharringtonine were as effective as the successive treatment with vincristine against P388 and L1210 leukemia, while both drugs were ineffective against Lewis lung carcinoma.

Alkaloids↗
PubMed1984

[Real-time two-dimensional Doppler echocardiography in congenital heart disease: its clinical significance].

This study demonstrated the diagnostic usefulness of the newly-developed real-time two-dimensional Doppler echocardiography (2-D Doppler) in congenital heart disease. Among fifty-four patients with congenital heart disease, 18 had ASD; 16, VSD; 6, T/F; 3, PDA; 3, d-TGA; 3, ECD; and 1 each, DORV, PA, PS, Ebstein's anomaly, and ruptured aneurysm of the sinus of Valsalva. Each diagnosis was confirmed by cardiac catheterization and/or surgery. Forty normal cases were subjected as the control. The study cases included 26 adults and 28 children under 15 years old, 13 infants and seven newborns. In 52 cases (96.3%) 2-D Doppler provided diagnostic abnormal intracardiac blood flow images which were compatible with the data of cardiac catheterization and cardiac angiography and/or patients' cardiac anatomy observed during surgery. The blood flow data obtained by 2-D Doppler facilitated determining the appropriate timing of palliative surgery such as the Blalock-Taussig shunt procedure. 2-D Doppler was effective in evaluating medical (pharmaco-echocardiography) and surgical therapy including radical and palliative procedures for congenital heart disease. Thus, 2-D Doppler proved a non-invasive and useful diagnostic method for congenital heart heart disease. Our data suggest that with this technique cardiac surgery can be performed without cardiac catheterization or cardiac angiography in some cases of congenital heart disease.

Adult↗
PubMed1983

A new technique in echocardiology: B-mode to M-mode transformation.

In conventional two-dimensional Echocardiography with sector scanning, M-mode is simultaneously displayed on TV-monitor as the time based ultrasound signals. With conventional system, one end of the cursor-line in B-mode image which indicates the beam direction of M-mode, is always fixed at the point corresponding to the transducer tip. This system has the capability to transform B-mode to M-mode images in any desired direction. However, the time resolution in M-mode is limited to about 33 milli-seconds.

Biometry↗
PubMed1982

Effects of Hoechst 33342 on survival and growth of two tumor cell lines and on hematopoietically normal bone marrow cells.

Our objective in this investigation was to determine whether Hoechst 33342, which is widely recognized as a DNA specific fluorochrome for living cells, is in fact nontoxic and kinetically nonperturbing at dye concentrations required to achieve acceptable DNA distributions. Three cell types were tested: HeLa S-3; SK-DHL2, a human lymphoma cell line; and hematopoietically normal human bone marrow cells. In the third system, only the cloning efficiencies were determined. Results differed considerably for the different cell types. While HeLa cells yielded excellent DNA distributions and were almost completely resistant to the cytotoxic and cytokinetic effects of the dye, SK-DHL2 cells were highly sensitive to the fluorochrome even at dye concentrations which produced very poor DNA distributions. Human bone marrow cells were intermediate in their stainability and toxicity response, and acceptable DNA distributions could be obtained at the nontoxic dye concentration of 2.5 muM. Clearly, different cell types differ considerably with respect to their cytotoxic and kinetic responses to Hoechst 33342. In some cases it may not be possible to ensure adequate staining of the cells for flow cytometry without significantly altering their viability and/or proliferative behavior.

Benzimidazoles↗
PubMed1982

[Application of flow cytometry to clinical oncology].

The application of flow cytometry (FCM) in the field of clinical oncology is reviewed. Since the development of the instruments, it has already passed more than a decade and, these days, FCM is utilized in a variety of fields, both basic and clinical researches. FCM has been getting familiar also in Japan for these several years and now more than fifty instruments are running in many laboratories. In this issue, the application of FCM to clinical oncology is described by several authors from different fields. In this review, the definition of FCM, the principle how it works, its advantages and the history of its development are briefly introduced. Furthermore, the application of FCM by measurements of cellular DNA content for estimation of cell cycle distribution and ploidy studies or by measurements of cell surface fluorescence for detection of cell surface antigens is reviewed in hematology, immunology, cell kinetics of cancer and chemotherapy, automated cytology, chromosome analysis and other fields.

Cell Cycle↗
PubMed1982

[Evaluation of 201Tl-accumulation in lung--imaging of 201Tl in the extravascular space (author's transl)].

In order to evaluate 201Tl-accumulation in lung, 201Tl imaging was performed using a scintillation camera coupling to a small digital computer, and blood clearance of it was examined. After the injection of 74 MBq(2mCi) of 201Tl-chloride, the serial images and static images were obtained. In order to obtain the image of 201Tl in the extravascular space [TE(x, y)], a subtraction technique was performed as follows; after 2 anterior views of 201Tl were obtained using a 20% window centered at 80 keV [T0(x, y)] and 140 keV [T140(x, y)] respectively, and blood sample was taken, radionuclide angiocardiography with 185 MBq (5 mCi) of 99mTc-human serum albumin and it's static image were done in the same supine position and blood sample was taken too. The radioactivity of 201Tl(T) and 99mTc(HB) in the blood was counted by a autogamma scintillation counter. Then the image of TE(x, y) was obtained by the following formula; TE(x, y)=T0(x, y)-[H(x, y)-T140(x, y)]TB/HB. Following results were obtained; (1) The disappearance of 201Tl from the blood was rapid and 15 min after the injection only 10 approximately 15% of the activity after 1 min was present in the blood. (2) The lung activity in the time activity curve decreased rapidly to reach plateau within 100 approximately 150 sec after the injection. (3) The image of 201Tl in the extravascular space was nearly equal to the original one as regard to the radioactivity of 201Tl in lung.

Adult↗
PubMed1982

[Flow cytometric analysis of cell surface antigens on leukemia cells by monoclonal antibodies and its application].

Nine monoclonal antibodies against null cell ALL cells were obtained by mouse hybridoma technique. Using two antibodies, namely B-1 and D-22, out of these, cell surface antigens on various leukemia cells, normal bone marrow cells, spleen cells and cultured cells were analysed by means of flow cytometry. B-1 antibody was found to have reactivities against null cell ALL cells as well as some CML-blastic crisis cells. The antibody reacted against some cultured lymphoid cell lines and also several percent of bone marrow cells. The reactivities of B-1 antibody were quite similar to those of c-ALL by Greaves et al and J-5 by Ritz et al. Radioimmunoprecipitation experiment suggested that B-1 antibody define the same antigen as the other two do. Meanwhile, D-22 antibody reacted against null cell ALL cells, but did not react against any other types of leukemia cells or any other cultured cell lines, or bone marrow cells. Thus D-22 antibody was considered to have higher specificity for null cell ALL cells than any other antibodies reported. On the other hand, the analyses by flow cytometry were well correlated with the analysis by immune adherence assay and by immunofluorescent microscopy. Besides, the analysis by flow cytometry provided us precise quantitative data and histogram pattern of positive cells. Furthermore, detailed examination of subpopulation could be done using cell sorter or other biological features could be analysed simultaneously using another fluorescent dye. Although, it has a few limitations, flow cytometry could take over other methods which are currently used in this field. Finally, the possibility of this method for the clinical diagnosis of leukemia was discussed.

Antibodies, Monoclonal↗